An access floor panel (180) comprises a central core (2), a lower tray (20), and an upper flooring lid (10) which form an envelope for the core (2). The panels have a fire resistant seal or barrier (25) for sealing between the tray and lid (20, 10). The ends of the tray and lid (20, 10) are kept apart and the barrier (25) seals against the core (2) and each of the ends (181, 182) of the tray and lid (20, 10) to complete the enclosure. The seal (25) acts as a fire stop.

29. An access floor panel comprising:— a core within a shell comprising a bottom tray and a top lid; the bottom tray comprising a tray bottom and tray side walls extending upwardly from the tray bottom; the top lid comprising a lid top and lid side walls depending downwardly from the lid top; the ends of the tray and lid side walls being separated and a barrier being provided between the ends.

30. The panel as claimed in claim 29 wherein the barrier is a fire resistant barrier.

31. The panel as claimed in claim 29 wherein the barrier forms a seal.

32. The panel as claimed in claim 29 wherein there is engagement means between the barrier and the tray and lid ends.

33. The panel as claimed in claim 32 wherein the tray and/or lid ends define a channel for reception of the barrier.

34. The panel as claimed in claim 32 wherein the barrier has a slot or recess for interengagement with the lid and/or tray ends.

35. The panel as claimed in claim 29 wherein the barrier extends proud of the side edge of the panel.

36. The panel as claimed in claim 29 wherein the lid end portion is wrapped around the tray end portion.

37. The panel as claimed in claim 29 wherein the tray end portion is wrapped around the lid end portion.

38. The panel as claimed in claim 29 wherein the barrier extends to an upper face of the panel to provide a panel side edge.

39. The panel as claimed in claim 29 comprising retaining means for retaining the barrier in place.

40. The panel as claimed in claim 39 wherein the retaining means comprises portion of the barrier.

41. The panel as claimed in claim 40 wherein the retaining means is integral with the barrier.

42. The panel as claimed in claim 41 wherein the retaining means comprises at least one formation on the barrier.

43. The panel as claimed in claim 42 wherein the formulation comprises a barb formation.

44. The panel as claimed in claim 39 wherein the retaining means comprises a separate component.

45. The panel as claimed in claim 44 wherein the separate component comprises a fixing means.

46. The panel as claimed in claim 45 wherein the fixing means comprises a staple or pin.

47. The panel as claimed in claim 29 wherein the barrier is bonded to the core.

48. The panel as claimed in claim 29 wherein the lid side and tray sides are substantially co-planar.

49. The panel as claimed in claim 29 wherein the lid side and tray side are offset.

50. The panel is claimed in claim 29 wherein the barrier extends substantially fully around the periphery of the panel.

51. The panel as claimed in claim 29 comprising an intumescent element or material.

52. The panel as claimed in claim 29 wherein the barrier comprises an intumescent element or material.

53. The panel is claimed in claim 29 wherein the barrier comprises a substrate or backing and an intumescent element.

54. The access floor system comprising a plurality of panels as claimed in claim 29.

Description:

The invention relates to access flooring systems of the type comprising a plurality of floor panels and a plurality of support pedestals for supporting the floor panels. Such flooring systems are used to define an underfloor chamber through which various conduits and wiring can be led, for example for various electrical or computer services and/or for conduits of an air conditioning system. The pedestals are distributed over a subfloor, such as a floor of a multi-story building and they are arranged to support the floor panels such that floor panels can be individually removable to gain access to the chamber below the panels. When assembled, the panels provide a relatively flat and strong floor to support office personnel and furniture.

There is a need for an improved floor panel which will provide improved fire resistance.

STATEMENTS OF INVENTION

According to the invention there is provided an access floor panel comprising:—

a core enclosed within a shell comprising a bottom tray and a top lid;

the bottom tray comprising a tray bottom and tray side walls extending upwardly from the tray bottom;

the top lid comprising a lid top and lid side walls depending downwardly from the lid top;

the ends of the tray and lid side walls being separated and a barrier being provided between the ends.

In one embodiment the barrier is a fire resistant barrier. The barrier may form a seal.

In one embodiment there is engagement means between the barrier and the tray and lid ends. The tray and/or lid ends may define a channel for reception of the barrier. The barrier may have a slot or recess for interengagement with the lid and/or tray ends.

In one embodiment the barrier extends proud of the side edge of the panel.

The lid end portion may be wrapped around the tray end portion.

The tray end portion may be wrapped around the lid end portion.

In one case the barrier extends to an upper face of the panel to provide a panel side edge.

In another embodiment the panel comprises retaining means for retaining the barrier in place. The retaining means may comprise portion of the barrier. The retaining means may be integral with the barrier. In one case the retaining means comprises at least one formation in the barrier. The formation may comprise a barb formation

In another embodiment the retaining means comprises a separate component. The separate component may comprise a fixing means. The fixing means may be a staple or pin.

In all cases the barrier may be bonded to the core.

In one embodiment the lid side and tray sides are substantially co-planar. Alternatively the lid side and tray side are offset.

In one embodiment the barrier extends substantially fully around the periphery of the panel.

The panel may comprise an intumescent element or material. The barrier may comprise an intumescent element or material.

In one case the barrier comprises a substrate or backing and an intumescent element.

The invention also provides an access floor system comprising a plurality of panels of the invention.

BRIEF DESCRIPTION OF DRAWINGS

The invention will be more clearly understood from the following description thereof given by way of example only, with reference to the accompanying drawings, in which:—

FIG. 1 is a cross sectional view of a portion of access floor panel according to the invention;

FIG. 2 is a cross sectional view of another floor panel of the invention;

FIG. 3 is a cross sectional view of a further floor panel of the invention;

FIG. 4 is a cross sectional view of another access floor panel;

FIGS. 5 to 14 are cross sectional views of further floor panels of the invention;

FIG. 15 is a cross sectional view of another floor panel of the invention;

FIG. 16 is a cross sectional view of a further panel;

FIG. 17 is a cross sectional view of another access floor panel of the invention;

FIG. 18 is a perspective view of the panel of FIG. 17; and

FIG. 19 is an enlarged perspective view of a corner of the panel of FIGS. 17 and 18.

DETAILED DESCRIPTION

Referring to the drawings floor panels according to the invention comprises a central core or substrate 2 which may be of chipboard or the like, and an envelope for the core 2. The envelope comprises a lower tray part 20 and an upper flooring lid part 10. The parts 10, 20 are separately formed, for example from metal sheets such as galvanised steel. The core 2 may be adhesively bonded to the upper and/or lower parts 10, 20.

The panels have a fire resistant seal 25 for sealing between the tray and lid 20, 10. We have found that by keeping the tray and lid parts 20, 10 apart and avoiding direct contact at the joint therebetween a significant improvement in fire performance is achieved. The seal 25 is positioned and configured to seal against the core 2 and the ends of each of the tray and lid parts to complete the enclosure. The seal 25 is in the form of a strip that extends around the peripheral edge of the panel. It acts as a fire stop for the floors, sealing the gap between adjacent panels. The seal 25 also acts as an air seal to prevent air transport across between adjacent panels. It also protects the upper steel skin or lid 10 against below floor convection currents. The seal 25 also provides a mechanical linkage between the steel skins 10, 20. In some cases, by selection of an appropriate material it can also provide an aesthetic finish for the perimeter of the upper surface of the floor panel, if this is the finished wear facing.

Separation of the top and bottom parts 10, 20 also stops direct conduction of heat around from the underside of the panel to the top surface.

The seal may also have sufficient mechanical strength to be included in the wrapping of the steel joint whilst still acting as a deflector for heat.

Alternatively the insulating separator may be a polymer, or ceramic, or mineral, or vegetable based product that has limited fire properties and a separate intumescent element is applied near to the base of the panel.

A further advantage of the design is that the sides can be made vertical and a gap provided between the panels by a secondary separator. This permits a further option, for some of the designs such that either surface of the panel may be used as a wear surface and thus the panel is reversible.

In the panel of FIG. 1 the ends 26, 27 of the lid 10 and tray 20 are inturned and then downturned/upturned to create a receiving channel for a seal 25. The joggled edge of the steel provides edge strength and the infill both seals the core against moisture ingress and locally prevents the steel edges from deflecting when subject to a bending load.

Referring to FIG. 2 the ends 31, 32 of the lid 10 and tray 20 are inturned and then downturned/upturned to create a dove-tail shaped channel for a seal 33. This configuration has improved joint strength and seal retention properties. The arrangement of FIG. 2 has similar advantages to the system of FIG. 1 with the added benefit of a mechanical lock.

In the panel 40 of FIG. 3 the ends 41, 42 of the lid 10 and tray 20 are configured to provide a channel which may be shaped like the channels of FIG. 1 or FIG. 2. In this case a seal 43 extends sidewardly of the edge of the panel. The seal 43 can be deformed in use for enhanced sealing. The seal may be of a compliant material.

Referring to the panel 50 of FIG. 4 the ends 51, 52 of the tray 20 and lid 10 are straight and a seal 53 has slots for reception of these ends. The seal 53 again projects proud of the peripheral side edge of the panel 50. A mechanical locking is provided.

The panel 60 of FIG. 5 is somewhat similar to that of FIG. 4 except that the seal 63 extends the full depth of the core 2 on the inside for enhanced mechanical strength and protection of the core 2. The edge provides additional edge strength.

In the arrangements described above the side faces of the lid 10 and tray 20 of the panels are generally co-planner. Various configuration with different arrangements are illustrated in FIGS. 6 to 13.

Referring to FIG. 6, in this case the end 71 of the lid 10 extends sidewardly and is downturned whilst the end 72 of the tray 20 is a straight end which is inboard of the lid end 71. The seal 73 provides fire resistance and mechanical properties at the joint. The tray 20 has additional panel strength.

In the panel 80 of FIG. 7 the end 81 of the lid 10 extends sidewardly and the end 82 of the tray 20 is a straight end that is inboard of the lid end 81. The seal 83 provides fire resistance, mechanical properties and also provides an air seal. The integrity of the edge trim provides a barrier.

The panel 90 of FIG. 8 has tray 20 side that is angled upwardly and outwardly to provide an end 92 which is separated from an end 91 of the lid 10 by a seal 93. The advantages are similar to FIG. 7. In this case the edge is protected from heat.

In the arrangement of FIG. 9 a panel 100 has tray and lid sides which are interfolded but separated at the ends 101, 102 by a seal 103. Because of the interfolding the joint has enhanced mechanical strength.

The panel 110 of FIG. 10 is similar to that of FIG. 9 except that the tray end 112 is a straight end and the lid end 113 is looped/folded for enhanced mechanical strength.

In both FIGS. 9 and 10 the advantages comprise thermal separation of the two steels but interlocked with an insulating membrane to provide additional edge strength.

Referring to FIG. 11 the lid end 121 and tray end 122 of the panel 120 are straight but the ends are offset. A seal 123 provides fire resistance and mechanical strength. Two layers of steel improve edge strength.

In the arrangement of FIG. 12 a panel 130 has a joint at a lower end thereof, a lid end 131 being extended into channel created by a tray end 132 which is offset from the lid end 131. A seal 133 again provides fire resistance and mechanical properties. The arrangement is similar to FIG. 6 but with improved insulation.

Referring to the panel 140 of FIG. 13, a lid end 141 is inboard of a tray end 142 and the outer face of a seal 143 is co-planar with the face of tray end 142. In this the infill is shielded by the lower steel. The infill also acts as an edge band.

In the panel 150 of FIG. 14, the tray and lid ends 151, 152 are straight and a seal 153 has a leg 154 which extends to the upper face of the panel to provide the additional feature of an aesthetically pleasing finished exposed edge to the panel. The locking is similar to FIG. 1 but an edgeband is also provided.

Referring to FIGS. 15 and 16 there are illustrated further panels 160, 170 of the invention. In these cases retaining means are provided for retaining the barrier 25 in place. Referring in particular to FIG. 15 the retaining means 161 comprises a portion of and in this case is integral with the barrier 25. The retaining means 161 comprises at least one formation on the barrier 25. The formations comprise barbs 162 for fixing the barrier in place. The retaining means may be a tight fit in a receiving hole in the core 2: These embodiments are similar to FIG. 1 but with additional mechanical locking.

Referring in particular to FIG. 16, in this case the retaining means comprises a separate component which may be provided by a suitable fixing such as a pin or staple 171.

Referring to FIGS. 17 to 19 there is illustrated another access floor panel 180 of the invention which is similar to the panel described with reference to FIG. 1 and like parts are assigned the same reference numerals. In this case a fire resistant seal 25 in the form of a strip is applied to the core 2 and the ends 181, 182 of the lid 10 and tray 20 are simply downturned to separately engage the seal 25. The ends 181, 182 of the lid 10 and tray 20 are separated by the seal 25 for enhanced fire performance. One particular advantage of this arrangement is simplicity of construction. The panel is also reversible. In this case the seal is of a plastics material bonded to the core 2, for example using a suitable adhesive.

A fire test was carried out on the panel of FIGS. 17 to 19. The panel reached Class RE130r under a 1.5 kN load in accordance with EN13501 part 2.

In some respects FIGS. 17 to 19 illustrate the simplest version which rely on material bulk for strength as opposed to geometry of the steel. The internal edge band serves as a gap filler only.

In principle the last of these is the most simple but most rely on the same response to heat: The lower steel tray, exposed to heat, expands and contacts the adjacent trays, also expanding, this protects the side of the panels from direct heat. The plastic, which may be ABS, simply melts away and gasses off.

The invention is not limited to the embodiments hereinbefore described which may be varied in detail.